The date code is 5 with no dots, indicating it was made in the last quarter of 1945. The parker arrow nib is smooth, feels like a medium to me. Add your favorite ink and write on 128mm capped, 150mm posted.
Other countries please inquire for rates and terms. This pen has been thoroughly cleaned, restored to working condition, and tested. I guarantee that, when you get it, it will hold ink and write; and i guarantee my workmanship and materials. Vintage pens from days of yore are fragile however, and i cannot guarantee that it will work or hold ink into the future. Your care will make the difference there.
And, of course, you're going to need a bottle of good ink. I will make every effort to resolve any issues. I want to earn a 5-star rating from you. Having grown up in a family stationery store, i came to appreciate fountain pens as an excellent example of american ingenuity, craftsmanship, and marketing, and have been collecting and tinkering with them for over thirty years.